Molded metallic core



May 17,1932. W, M DUNCAN 1,859,078

MOLDFD METALLIC Filed Jan. 19, 1931 INVENTQR QWLM Ma bmm BY 7,

A TT ORNE Y Patented May 17, 1932 WILLIAM M. DUNCAN, on ancient, rumors MOLDED METALLIC CORE.

Application filed January 19, 1931. Serial No. 509,705.

'This invention relates to certain new and.

useful improvements in molded metallic cores foruse in molds for cylindrical and other forms of castings, the peculiarities of which Will be hereinafter fully described and claimed.

The main objects of my invention are first, to provide a core comprising ferrous metallic particles, and a suitable binder; second, to vary the proportion of saidmetallic partlcles intermixed with core sand soas to'vary the chilling effect accordingly on the poured casting; third, to provide such a core with a preponderance of metallic particles for chilling the outer surface of a comparatively thin portion of the casting formed between said chilling core and another core spaced therefrom and adapted to shield it from the body of the casting; particles of iron or'other suitable metal in various proportions to the core sand intermixed therewith and held together by linseed oil or other suitable binder; fifth, to reclaim the metallic particles from the core as disintegrated after use; and other objects hereinafter fully described and claimed.

The ordinary chill of solid metal is either.

in one piece or in sections disposed in the mold where an effect is desired on the poured casting. My metallic composition core consists of iron borings or other suitable metal reduced to sandlike particles and held together by a binder, or forming various percentages of the core when intermixed with core sand and molded with a binder of linseed oil, or a suitable core compound, in a similar manner to that employed in making,

dry sand cores. The percentages of metallic particles in such cores would likewise vary the chilling effect from a maximum when a preponderance of metallic particles is used, to a lesser chilling effect by a lesser percentage of metallic particles employed in cases where'it is desired to give a dense impervious iron casting, rather than a chill of the same. By varying the percentage of iron in my molded metallic composition cores, the chilling action can be controlled so thata dense grey iron can be produced as well as a chilled surface.

. plastic inits initial state. It would thus refourth, to use fine, ground up "my metallic composition chill A chill of this kind could be used wherever a core could be used. In other Words, a chill could be produced on a casting wherever desired as my metallic composition core is place sectional chills due to the fact that it can beremoved just as a core is removed. Heat would destroy. the binder and the iron or other metallic articles forming the base of the disintegratable core .could? be re- 00 claimed by a magnet for further use, if such metallic particles used are magnetic as is the case with ground up iron borings which preferably form such a base.

' Referring to the drawings on which like reference numerals indicate corresponding p t Fig. 1 represents a section of a mold con taining a flat plate casting having holes therein such as a sintering machine grate bar, and" my metallic composition core. applied thereto;

Fig. 2, a Water jacketed cylinder as poured in a mold with my improved cores applied thereto;

Fig. 3, a similar view of a rope sheave with applied to the grooved face of the rim; and

Fig. 4, a, similar view of a roller having a sleevelike outer portion spaced from the body of the'roller, and my metallic composition chill applied thereto.

Referring to the drawings, the numeral 1 represents a flat plate having holes 2 therethrough, the surfaces of which it is desired to, chill, such as in a sintering machine grate bar where down draft suction through the holes draws coke dust and iron ore, thus enlarging them by the abras i e action thereof in an incredibly short time to such proportion that the grate bars are made useless. When a composition'ofmetallic and nonmetallic material containing a suitable percentage of metallic particles as shown at 3 Fig. 1, are used in .said holes, a corresponding chill is obtainedin the poured casting at.-5, as indicated at the right in Fig. 1.

In Fig. 3, the rim 6 of a rope sheave in which it is essential for effective use the the grooved surface for a hard face, has my partially metallic chill 7 shown applied thereto.

claimed after use,

ted altogether,

In Fig. 2 showing a water jacketed cylinder, the central core 8 and chamber core 9, are formed ofmy partially metallic core containing a suitable lesser percentage of iron particles so as to obtain a lesser condensation of the metal without the former chilling effect of a larger percentage of iron particles.

In Fig. 4, a'roller 10 is provided with a partially metallic core 11 as a lining for the surrounding mold, and such lining contains a large percentage 'of metallic particles so as to produce upon the outer sleevelike cylindrical portion 12, the desired density and chill capable of withstanding abrasion.

In this construction of roller, the said sleevelike outer portion 12 is spaced from the body 13 by a. core 14 having holes 15 therethrough to form connecting bridges between said outer and the inner portions. This inner core 14, concentric with the sleeve port on, contains a reduced number of metallic particles in the core mixture, or may dispense withthe same. The object of this construction of cylinder is to shield the outer chilled portion of the 'poured'castiiig ,from the heat of the body of the roller. The central bore 16 may to the core 14.

I have made such core chills containing ulverized ironborings and there has been no difliculty experienced in making good smooth cores. I have also illustrated herewith the application of my partially metallic core to various forms of poured casting. v In such cores of my construction the iron or other magnetic particles are reclaimed from the core sand after the heat of the casting has destroyed the binder, and such particles are available for further use.

\Vhen my molded core is mainly composed of metallic particles, and intermixed core sand is reduced to a minimum or omitand the maximum of metallic particles are held together by linseed oil or otherwise, a fracture examined by a low powered microscope shows a structure closely coarse grained cast iron. Such a resembling an initial plastic core as molded or cast in state, will produce a maximum chill in a yet the particles can be refor later cores of various proportions of said particles as the base. While I may provide my cores having intermixed iron particles as stated above, in the usual dry condition of ordinary dry sand cores, I may use my partially metall c core otherwise than in such usual dry condition under other circumstancesv andrequirements, but have given these illustrations and description of the same as the preferred form of carrying out my invention. I therefore poured casting,

do not limit myself to the construction shown except as by the claims herewith.

be of similar composition I claim:

1. The combination with a mold, of a chill core comprising a mixture of fine metallic particles and sand held together by a suitable binder and disposed in said mold at the place where-a chill is desired'in the pouredcasting, and another core disposed in said mold and spaced from said chill to shield the resulting chilled surface of the interposed portion of said casting from the heat of the body of the casting, substantially as described.

2.- The combination with a mold, of a chill core comprising a mixture of metallic particles and sand and a suitable binder and disposed in said mold where a chilled surface is desired in a comparatively thin portion of a casting, and an inner corespaced opposite said chill and having through holes to form connecting bridges between said thin porti on and the body of the casting,-substantially as described.

3. The combination with a mold. for a cylindrical casting, of a metallic core lining the outer surface of said mold to form a chill on'the poured casting, asleevelike cylindrical core spaced from and concentric with the outer core to form a comparatively thin portion of the casting and having holes to form connecting bridges between said thin portion and the inner'body of the casting, and a central core to form the bore of the casting, the said sleevelike core shielding the chilled outer'surface of the thin portion of the cast-- ing from thelieat of the inner body, substantially as described. a

In testimony whereof I have aifixed my 

